Containers for refilling use, in which a fluid material such as a liquid is hermetically packed and, in using the contents of the bag, is transferred into another container such as a bottle, preferably satisfies the requirements that the contents of the bag can be transferred easily and safely and, at the same time, the containers are inexpensive, the empty containers are not bulky, and the containers after use can be easily disposed of. For example, bags comprising, for example, a flat bag or a self-standing bag, formed by heat sealing a laminated film, and a narrow-width spout port, the periphery of which has been heat sealed, provided in a part of the circumference of the bag, have hitherto been used.
The above bags with a spout port are advantageously inexpensive and have excellent productivity, but on the other hand, they suffer from problems that the easy opening properties of the spout port and the shape retention of the opening are poor, the spout port is likely to be clogged in the course of spouting of the contents, and, thus, the suitability for spouting of the contents is poor.
Various studies have been made to solve the above problems, and bags improved in the suitability for spouting of the contents, for example, in the easy opening properties of the spouting part and the shape retention of the opening, have been proposed.
For example, a bag comprising a groove-shaped recess for forming a flow passage in a film material in a spout port of a bag, and a small tube such as a plastic small tube fixed in the groove-shaped recess for preventing the collapse of the flow passage and for withdrawing the contents of the bag through the small tube and emptying the bag has been proposed (see Japanese Patent Laid-Open No. 132069/1993 on pages 2 and 3, FIG. 1).
Further, a pouch for refilling, comprising a spout port part provided in a part of the upper part of a pouch, and a reinforcing member, provided in the internal face of the spout part, which is flat when mounted and, in use, is deformed to a tubular form to open the spout port part, has been proposed (see Japanese Patent Laid-Open No. 79195/1999 on pages 2 to 7, FIGS. 1 and 3).
The claimed advantage of the bag described in Japanese Patent Laid-Open No. 132069/1993 in which a groove-shaped recess is provided as a flow passage in a film material of a spout port part and a small tube having a certain level of hardness formed of, for example, a plastic molded product is fixed into the recess, is that the collapse of the flow passage can be reliably prevented and, at the same time, the contents of the bag can be spouted through the small tube.
However, in this bag, in providing a groove-shaped recess, the film material should be subjected to deep drawing in the course of the production of the bag, and, in inserting the small tube for fixation, spot welding is necessary. Accordingly, the production apparatus is complicated, and, at the same time, the production rate is also limited. Further, the small tube is hard and cylindrical, and the outer diameter should be not less than about 5 mm. Therefore, only the spout port part in the bag is bulky, and this is unsuitable in the handling or storage of an empty bag. Further, a special apparatus is also necessary for the feed apparatus of the empty bag in a filling sealing machine in the filling of the contents. Accordingly, the production equipment is complicated, and, at the same time, the production rate is reduced, resulting in increased production cost. Also from the viewpoint of quality, the above bag is disadvantageous in that, in some cases, the film material for the bag is damaged at the end of the small tube due to high hardness of the small tube.
Further, according to the pouch for refilling use described in Japanese Patent Laid-Open No. 79195/1999, a rigid sheet such as plastic is used as the reinforcing member. As shown in A-1, B-1 and C-1 of FIG. 3 in the above publication, the rigid sheet is fabricated, and the flat reinforcing member is applied to the inner surface of the spout port part in its predetermined part. In use, for example, pressing from both sides of the pouch toward the center part causes the reinforcing member to be deformed into an angular shape as shown in A-2, B-2, and C-2 in FIG. 3, and the spout port part can be opened in a prismatic form with good shape retention.
Even in the pouch for refilling, when the number of days of storage is long and is a few months or longer after the production, a high torque is necessary for gradually deforming the reinforcing member. This makes it difficult to deform the spout port part in use into a prismatic form.